When silica dust is inhaled, the particles become lodged in the alveoli, the tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged. The body's immune system responds by sending macrophages to engulf and digest the particles. However, silica is toxic to macrophages, causing them to release inflammatory mediators and die, resulting in fibrosis, or scarring, of lung tissue. This process can lead to progressive lung damage, even after exposure has ceased.
